Buccaneer is another name for "pirate." When you're sailing the open sea, you might worry about a buccaneer who wants to rob your ship and possibly enslave your crew.
In the late 17th century, a buccaneer was a specific kind of pirate. Buccaneers generally stayed in the Caribbean Sea, while pirates roamed the Indian Ocean. Buccaneers were also more likely to attack coastal cities. Perhaps in those cities, they learned to smoke meat, which is the meaning of the French word boucanier and the Native American word bukan. Buccaneers were known for eating smoked meats.